Flow meter and method of making same



May 20, 1930 M.'MORRISON I I FLOW METER AND METHOD OF MAKINGYSAME Filed ow s, 1925 5 Sheets-Sheet, 1

y 1930- I M. MORRISON I 1,759,239

FLOW METER AND METHOD. OF MAKING 'SAME Filed Oct. 8, 1923 5 Sheets-Sheet 2 .May 20, 1930. M. MORRISON 1,759,239

FLOW METER AND METHOD OF MAKING SAME Filed Oct. 8, l923 5 Sheets-Sheet 3 May 20, 1930.. M. MORRISON I FLOW METER AND METHOD OF MAKING SAME Filed Oct. a, 1923 s Shets-Sheet 4 May 20,1930. M. MORRISON SLOW METER AND METHOD OF MAKING SAME 5 Shets-Sheet 5 Filed 001;. 8, 1923 Patented May 20, 1930' UNITED STATES PATENT OFFICE.

MONTFORD MORRISON, OF CHICAGO, ILLINOIS FLOW METER AND METHOD OF MAKING SAME Application filed October 8, 1923. Serial No. 667,397.

. measured in such a way as to resist thelatitudinal components of the velocities of flow and assist in the equalization of the longitudinal components of the said flow, thus improving the velocity distribution for meas urement; second, to provide novel-and improved form of dynamic pressure tubes, which maintain the aforesaid improved velocity-distribution and in addition integrate the dynamic pressure over substantially the entire field of flow, thus giving an improved measure of the flow; third, to provide an improved chamber for my dynamic pressure tubes, Which'chamber modifies the velocity of flow at the said dynamic-pressure tubes insuch a manner as to improve the constancy of the calibration coefficient of the said tubes thus permitting of improved accuracies at' loW velocities-as, Well as at high velocities;

fourth, to provide means for eliminating. from the static pressure of the manometer,

' the pressure losses in the line thus greatly improving the relation of the differential pressures in the manometer to the rate of flow of the fluid. Y 40 of the velocity modifier and dynamic pres To illustrate the scope of my flow-meter, invention as related to my electrical instru-v substance of my invention is more fully dis closed in the appended claims.

The present application forms the parent case of several co-pending applications which cover the subject matter of this specification notcovered in the appended claims.

Reference may be now made to the drawings in which, Fig. 1 considered jointly with .Fig.-- 4,. constitute diagrammatical sketch of one embodiment of my invention and in which the elements have beenso modified, rearranged and simplified to general explanatory essentials, as is thought best to clearly present the differentiating characteristics of my invention in such a manner as would en- 6 able one skilled in the art to make and use my invention.

' Figs. 2 and 3 are details of the embodiments sure tubes of Fig. l.

Fig. 5, is a general cross-section of the manometer shown in elevation in Fig. 1 and Figs. 6', 7 and 8 are construction details of Fig. 5 and will serve to illustrate method of making same.

Figs. 9 and 10 are difl'erent elevations of some of the elements of the integrator shown I in Fig. 4, the parts being modified, rearranged and simplified for clearness, as in an actual integrator, the relative proportions of the parts and their compact disposition together with the supporting structure, do not lend themselves readily to easy conception and comprehension.

'Fig. 11' is an elevation of. the recording dials of integrator shown in Fig. 9.

Figs. 12 and 13 show a second embodiment of my invention in the form of an integrator combined with a recorder and an indicator and having a single electric circuit element, all ofwhich are widely different mechanically from the construction shown in the embodiment illustrated in the preceding figures, though entirely within ment of Fig. 12. v I

Fig. 15 shows a third embodiment of inresents a flow indicator, though this same element may be used in any of the instru ments shown in Fig. 4, in place of the elec-' trical elements illustrated in that figure.

It was shown by Rayleigh in 1876 that the dynamic pressure, exerted upon such a device as a Pitot tube by the velocity of a compressible fluid, is entirely different and follows a, different law'from that of a non-compressible fluid. However, Rayleigh pointed out that under, certain conditions of flow the law of the dynamic pressure of the compressible fluid is substantially that of the noncompressible fluid.

In my invention, I provide such a construction as will, where possible, reduce the average velocity of flow to within limits where .this dynamic pressure more nearly obeys the simple laws of non-compressible fluids for gaseous fluids.-

Of course this modification may not be necessary in the case of non-compressible fluids, but this aforementioned relation as pointed out by Rayleigh is very complex, and does "not lend itself readily to commercial metering. -So that in the cases where compressible fluids, such as gas, steam and air, are to be metered, and further where possible, I employ a mechanical construction in the vicinity of-myv dynamic pressure tubes such as will reduce the velocity of flow by thesesaid tubes, to within at least such a limit as will increase the accuracy of the dynamic pressure indi: cated, as related to the velocity of flow.

I also provide inthat part of my instrument which is inserted into the 'line of flow, one or more stages of the velocity distribution modifiers, which cause the velocities across the section of the line of flow to be more evenly distributed than without the said modifiers, so that when the stream lines reach my, dynamic ressure tubes to have their velocities recor ed, the variations in velocities have been considerably reduced, and the average-velocity more nearly corresponds to the maximum, and further, all-the velocities are of such a magnitude as lend themselves to more accurate dynamic-pressure-velocity re lations.

Further, I prefer to'employ' forms of dynamic pressure tubes which tends to maintain the stream lines o'f fiow in their modified directions and magnitude rather than disturb pressure device do not have their direction them, so that the fluids in passing my dynamic or magnitude -substantially modified, thus against increasing the accuracy of my device.

In my flow meter I provide a novel form of integrator, which belongs to a class of constructions as related to this art, rather than to a specific mechanical construction, and I submit two widely difierent embodimentsto illustratethis point.

In the first embodiment, I employ a timing mechanism which constitutes a shaft driven locity of the fluid to be metered.

In general, in my invention, I employ two electric fields, which react, one upon the other, in such a way as to serve as a means of integrating, recording or indicating the fluid flow by pure virtue of the relative arrangements of the fields, and independent of their intensities. That is to say,- I provide a class of constructions which accomplish the afore mentioned results independently of field intensity, and solely by the relation of one field to the other, or in shorter language, the field circuits are so constructed and operated that the results produced are proportional to one dependently of their numerical magnitude.

By employing such a principle, it is obvious to those skilled in the art that the results accomplished by such a construction are en-- field be supplied through a circuit which acts as a reference for the circuit through which the other field is supplied, and further that these two circuits are similar, electrically.

- In a case of embodiment in which t 1e resistment itself be not an influencing the entirecircuit, it is immaterial what the characteristics of the other parts of the electric circuitbe, provided the two circuits com-- pared are similarly conditions.

In the first embodiment of my instrument, I employ'for-the electrical elements used two responsive to electrical field-intensity divided by the other, and in J ance, inductance or capacity of the m er eleco-operating fields used in conjunction with w an armature in such a way that the position of rest assumed by the armature is proportional to the tangent of the angle between position assumed by the armature and the reference point, under which condition it will be appreciated that the tangent of the angle remains fixed independent of the relative intensities of the fields, and though these relative intensities might vary considerably, due

to line fluctuations, and the like, the position of rest of the armature for any particular relative current is not changed. Such a form of device is applicable to all three types of instruments, as will be brought out and set forth in this specification in the description of the particular embodiment involved.

The utilization of such a principle in a recorder and indicator is obviously advantageous to those skilled in the art, for since be calibrated in a cool room and operated reading.

Obviously, such a device is independent of such an instrument may, because it operates independent of field strength, work in very intense fields at all times and the indications may be made very accurate on the lower part of the scale which is not true of the common forms of instruments employed in the flow meter art.

The scales of the recorder and indicator may be spread out on the first part and crowded on the last part, in contradistinction to the others used in the art, which are crowded on the low part of the scale and spread out on the high part of the scale. Such instruments have very weak and uncertain deflections of the lower part of the scale, making themalmost useless, for low springs and the like, and does not have large temperature errors which makes them particularly suitable for the measurement of steam and the like, where the instrument may under considerable temperature.

' Due'to the high torqueof the instrument, it is entirely practical to gear the armature of the electrical elements to a small pinion on the shaftof the pointer of the instrument, and thus gives as long a scale as desired, with substantially the same or different scale characteristics depending upon whether I employ constant ratio or variable ratio gearing.

The great torque of such an instrument lends itselfto very rugged construction, such as is necessary to flow meter installations.

lVhat has been said about the indicator with its type of electrical element can also be said about the recorder. I An appreciable drag on the pointer of the recorder is not a considerable obstacle to the operation of such an element, because of the abundance of torque for all deflections. Unlike a spring opposed instrument, which has very small and uncertain torque at low de-, fiections, the low deflection records made by this instrument can be'depended upon because of this aforesaid abundance'of torque. lVith reference to the second embodiment of my integrator, which also has combined with it arecorder and an indicator, I will proceed to show that the characteristics of the electrical elements are the same as that afore discussed. This will be brought out in considerable detail in the description of illustrative embodiment.-

In the construction employed in this integrator I have provided a motor elementconstruction, which lends itself not only to good characteristlcs on direct current c1rcu1ts,'but also usable characteristics on alternatlng current circuits.

acteristics. Unlike other motor elements used in meters of prior art in measurement of the flow of fluids, and which prior art meters had very little torque, and in which the speed was fixed by the damping arrangements, in general in this motor element, as

. a matter of fact, it can be said that the electric fields may be more intense at low speeds than at high speeds, whlch makes greater 'accuracy possible at-light loads, a second characteristic commonlto both embodiments of my invention, as herein illustrated.

It will be appreciated by those skilled in the art that the first mentioned meter element may be used as one element in a con1- bined instrumentas well as the second em bodiment-that is to say, if the integrator,

ple or combined movable field. Such an arrangement may give more torque under some conditions of operation and connection, and

may give a greater direct spread of the scale,

where a composite, movable field isutilized. Under some conditions of simple field adjustment and construction, a scale somewhat similar to the firstembodiinent is obtained; and with a composite, movable electromagnetic field, I obtain a scale which is more nearly uniform, being slightly crowded at each end, all of which will be fully described under the discussion of this particular embodiment with reference to the drawings. a

It will be appreciated by those skilled in, the art that many different combinations may be made from the various elements of invenf tion herein described and to be described, and it is desired to particularly point out that the elements of this invention which relate particularly to the electrical instrument and the circuits connected therewith, are more particularly and fully described with reference to their diflferentiating characterlbs gas, and due to the fact that my instrument contains many elements which make it particularly applicable to the measurement of. these more diflicult fluids, I shall confine the discussion and specification to the measureing between them where it'is advantageous or desirable for the sake of comparison or clearness to the specification, as the scope of my invention with reference to this particuflange and an enlargement similar to'6 being eliminated from the left hand side of this in excess of the normal areas of the lar phase'is pointed out with particular accuracy in the appended claims.

Reference may now be made to the particular embodiment of my invention as illustrated in the drawings, in which Fig. 1, 1 is a gas'holder, 2 is a pipe line conducting the gas from'the holder to a distant receiver in the general direction of the numeral 3; the pipe line as illustrated is broken at 4:, and that part of the line which follows 'is considerably enlarged for clearness and is illustrated by 5. The relative size of the pipe l drawn on an enlarged scale of the same as part 5, would be of the size 6. the

In the figure thefflow of gas is from left to right, and into the pipe line, I insert the part5, which expands into a considerably greater diameter 7. This increase of diameter has the property of decreasing the velocities before they enter my dynamic pressure tubes, and in addition, I may bring the crosssectional area of, the parts through which the gas must flow up to, or even greatly in excess of, the cross section of a normal pipe line: a

Also, this provides means for measuring the velocity of flow onia considerably reduced velocity basis, which I find increases the accuracy of a'dynamic pressure tube measurement.

Beyond this expanded pipe part 7, on the down stream side of this pipe part, is the first stage of a velocity modifier 8. Fig. 2 is an elevation of the said part 8, taken from the up stream side thereof. This-pressure modifier is of a cellular construction and in the embodiment shown comprises crossplanes 9, Figs. 1 and 2, and these cross-planes may be provided with sharp edges on their up and-down stream sides, 10.

In general the areaof the combined cells taken as cross sections in the line of flow are ipe 4.

It will be appreciated by those ski led inv the art that the resistance ofiered tothe flow of fluids in pipes is proportional to some law relating to the velocity of flow, and

it can'be said, as a general statement, that the resistance offered to the flow of fluids in pipes over a great range of velocities increases faster than does the increase of velocity, and I employ a construction utilizing this 'rinci 1e in the velocity of modifier 8.

VY fth re erence to the longitudinal velociand applicable,

ties in the pipe, independent of turbulency of flow, it can be said that the gas in the center of a pipe is moving at a greater vestream line at 11, than one at 12, and if the flow at 12 be greater than that at 13, more.

resistance is offered at 12 than at 13 to the flow, so that the general effect is for the high velocity stream line to tend to flow-toward the low velocity stream line, thus having the effect of equalizing the distribution of velocities over the cross section of the pipe. 14 and 15 are second and third stages of the velocity modifiers, and may be similar to stage 8.

It will be appreciated .by those skilled in the art that such a construction offers great resistance to the turbulency of flow, and by properly proportioniugsuch stages, the turbulency of flow maybe thus greatly reduced.

It will be appreciated that the exact construction illustrated herein does not represent the limiting characteristics of my invention, as I might just as well construct these velocity modifiers all in one piece, with lateral holes connecting? the cells, or any construction which localizes the resistance to the stream lines of flow, such as to make the local resistance increase with increased velocity, and provide means'for'assisting in the redistribution of these velocities when the said 10- cal resistance is offered to them. Further, in some cases, where the average velocity encountered is very low, I may so construct these velocity modifiers that after reducing the average velocity sufiiciently, the diameters in these cells in these velocity modifiers are such that they are below the critical value, as given by Reynolds, in his'well-known paper published in 1883. I

. When the stream lines of flow have reached the plane 17, they are in their final modified form, and are ready to be measured upon the dynamic pressure tubes. My dynamic pressure tubes are distributedover substantially the entire cross section and at right angles to the line of flow at plane 17 and in general arein line with the cells of the velocity modifiers. With a large number of tubes distributed over the'entire area and substantially in line with the .velocity modifiers described, it will be appreciated that the stream lines are not disturbed materially in their directions and continue through these tubes in their modified forms.

. Unlike the dynamic pressure tubes of the prior art, I conduct the fluid through the struction that the flow is integrated over the entire cross section, at right angles to the izo the direction of flow. A

longitudinal direction of flow. Independently of whether great uniformity of velocity is obtained or not, the reading of the dynamic pressure tap is much more accurate than with tubes in the prior art which at the best only take into account openings in a line across dynamic pressure tap is shown at 18, and the tubes through which fluid flows are shown in section at 19 and in elevation at 20, and an up-stream ele- Vation of the dynamic pressure tubes is shown in Figure 3, and therein is shown their approximate location and general distribution.

In my invention I have provided two static pressure taps, one at 21 and one at22. It will be appreciated that the static pressure recorded at tap 21 includes all the drop in head due to that of the entrance of the pipe 22 at the gas holder 1, the friction in the pipe line 2, the loss due to the elbow and various other conditions which may be peculiar to the particular construction of pipe 'line used, and it is at once apparent that it will be impossible to take similarly calibrated meters and .expect them to read correctly on all pipe lines. This explains the apparently heretofore inexplicable reason why similarly calibrated meters should read different on different pipe lines.

I also provide valves 23 and 24, which allows me to utilize either static pressure tap I desire. In the utilization of the static pressuretap at 22, or at least one further disposed up stream than tap 21, I eliminate substantially all errors introduced into the instrument due to pipe line losses.

'However, I appreciate that it is not always practical or desirable to make a static pressure tap at 22, or even remotely disposed from the dynamic pressure tap along the up-stream line of the pipe, and for this reason I have also provided the pressure tap at 21,- which is the usual practice. Pipe 25 is the dynamic pressure connection for the manometer 27, and pipe 26 is the static pressure connection for the sa-id'manometer. In this description and specification of the instrument, the applicant has purposely omitted some details, such as means for taking care of gas condensation and the like, as such means are not an essential element of this invention. It is believed that such a detail and such similar small details would add nothing to the value of the specification.

Referring to Figure 5, I will discuss th principal elements of the manometer 27 of Figure 1. In the embodiment of my manometer invention herein illustrated I provide a general metal casing 27, which encloses substantially the entire device; 25 is the dynamic pressureginlet, which communicates the said pressure to the chamber 28, which is partlyfilled with some liquid such as mercury 29.

26 is the static pressure inlet to the manometer, which communicates the said pressure to the space above the mercury level 31. The

mercury level onthestatie pressure side of the manometer is indicated by the line 31, as before referred to. The communication between dynamic and static pressure chambers ispreferably restricted to a small opening, such as indicated at 32. This small openingconstruction prevents the mercury from being transferred from one chamber to another with any great degree of rapidity, which has the effect of dampening out oscillations in the differential mercury column, due to pulsations in the flow of the fluid to be measured. In the opening 32, is located a double acting check valve 33, which is held in a neutral position by means of spring 34, and should there be a tendency for the sudden rise of mercury ineither direction through the opening 32, of suflicient magnitude to force the mercury beyond its normal working'limit, the double acting check valve 33 closes the opening until pressure has been removed, thus tending to prevent the mercury from being blown out under certain conditions in ractice.

In theembodiment, illustrated herein, of my manometer, I provide an immersible coil of wire 35, which has its several turns shortcircuited by the rise of mercury in the chamber above 31. I I may provide my manometer with an insulated bushing 36, which serves as an insulated electrical connection from the thumb nut at 36 to the beginning of the resistance coil 37. The resistance coil beginning at 37 is wound spirallyand helically around a surface of revolution. according to certain laws hereinafter described, and ending at the point 38. My resistance coil is so constructedthat as the mercury rises in the chamber 30 due to the differential pressure in the manometer, as the said mercury short circuits the turns in the coil 35, the turns abovethe mercury level in chamber 30 have an electricalconductivity which, when referred to as standard, is proportional to the velocity of flow in the pipe line 4.

Mathematically, there are several ways of arriving at the dimensions of such a coil of Wire, and two of which I will explain herewith.

Referring to Figure 7, the maximum pressure difference to be measured is indicated on the diagram by the legend, and it is desired to find the intersection in the H plane of a surface of revolution, which, when it has a resistance wire wound upon it will give such a length, measured fromone end of the winding to any fraction of the total thereof, as will allow it the desired conductivity.

Obviously, the pitch of the thread 8, which constitutes the path of the resistance coil,. might follow any law whatever, but in order totake advantage of standardization in the existing machines, I may use a constant pitch along the w-axis, in which case, I obtain a path for the wire, which when projected in. the w-jz] plane, is the curve indicated. in the figure for 8. Curve r is the intersection of a surface of'revolution around which thread 8 is cut. I have solved the problem of deducing the equation for the dimensions of such a coil for any relation whatever between the velocity of fiow in the pipe line 4, Fig. 1, and the dynamic pressure in the manometer 27. My

'0 result is represented by equation a in Figure 7. .As I have heretoforepointed out, this afo ementioned relation may be very compli'c'ated in form, and therefore I provide a special equatlonfrom the solution of which I may obtain desirable values.

When the conditions of flow in the pipe line 4 are such that the square law holds suflicientlly' true between the velocity of flow and the ynamic pressure, I may use equation I), Fig- 'ure 7, which represents mathematically-the relationsunder these conditions.

I have solved this equation numerically, and print in column 0 the numerical values of the various ordinates of the'curve. It will be appreciated by those skilled in the art that the utilization of a surface of revolutions for this resistance coil is not absolutely essential,

' to come within the scope of my invention, as the cross section of this coil ma have any form whatever, but the surface-o -revolution figure is used because of its constructive simplicit and practical importance.

Re erring to Figure 8, it will be observed that instead of using a constant pitch along the w-axis, as illustrated in Figure 7, I may use a constant pitch along the intersection of the surface of revolution 1* in one of the reference planes, .as illustrated in Figure 8,

by the equally spaced lines along the interthe w plane. Such a construction may prove to be very useful in certain cases, and.

therefore give the equation for this form of resistor for any velocity pressure relation and show it on the line 'a Figure 8. Line I) 'ves the equation for a square law relation etween the aforesaid velocity and ressure. Regarding some of the practical etails in the method of making such a resistance coil which would be operative under the conditions imposed upon it in this invention, refer to Figure 6, which is an enlarged segment of the'section at 39. v

This spool 39 upon which-the resistance coil is wound, has molded or cut. into its outer surfaces an openv thread or groove which has'for its direction, dimensions, etc., those set forth in the equation given in Fig. 7 or Fig. 8, and into which the resistance wire is to be wound. a

Referring to Fig. 7, a is a general mathematical expression which I have deduced I to calculate the eometrical path'of the wire 35in Fig. 5, an equation is a particu- 55 lar form of equation a expressing the difvalue of w.

sistor is illustrated in Fi prises a surface of revolut on permittmg asection of the said surface of revolution in ferential geometry of the path of the wire as related to its co-ordinates for a CV velocitypressure law for a coil having a uniform thread pitch along'the an axis. 1' is the radius of the coil in the yz plane for any connecting the constants of the differential pressure creating device and the constants of the manometer with the differential geometry of the resistance coil described.

' In Fig. 8 equation a is a mathematical expression corresponding to that of.a in Fig. 7, but for a coil having a variable thread pitch. 6 is a specific equation for a CV law corresponding with equation 6 in Fig. 7. In Fig. 8, the form of the surface 1' depends upon the law followed for the variable thread pitch. Quite obviously the thread pitch may vary in accordance with anylawprovided it is mathematically related 2 is a calibration constant properly to the geometry of the surface 1" which will therefore depend upon the mathem-atical'law followed for the thread pitch. An example'of this type of manometer re- 8, which comconstant pitch as a function of the trace of the surface of revolution. The variables and constants of equation 6, Fig. 8, correspon with those of equation b, Fig. 7.

It will beappreciated by those skilled'in the art, that resistance wire is found to vary in actual resistance from lot to lot, and to take care of this, I select a piece of wire of alength and resistance slightly under that required for the coil. This wire is then grasped at certain places and stretched with a resistance measuring instrument in circuit and the stretching operation is continued until the resistance measuring instrument indicates a certain .value, still somewhat less than the ultimate value required.

This resistance-wire is composed of any suitable material with a slight coating of varnish insulation, commonly known as enamel by .users of resistance wire. The wire is then wound into the thread of the spool, and when wound has a total resistance slightly lower than the ultimate desired value. The spaces41, Fig. 6 between the wire 40 and the spaces 42 above said wire are completely filled with varnish or other suitable insulation and then fixed into a solid -mass by oxidization or some other process, -Wl11Ch gives astructure of reslstance (5011 which is entirely embedded'within a solid mass of insulating material, giving such an sulating material is removed from the resistance coil along the line 43, which is comprised of-the wire with small flat spots, 44 The actual calibration of the total resistance of the coil is effected by cuttingfurther into the coil along the line 43, making broader surfaces at 44, until the proper exact resistance is obtained, thus providing a resistance coil embedded into a solid mass of mechanically strong insulating material, and calibrated after being wound in place.

The wires having only small surfaces exposed at 44 to the action of the mercury, entirely eliminate the. short-circuiting of a turn due to the mercury otherwise adhering in the spaces between them, as has been experienced in the prior art.

To understand the principle of an embodiment of one of my integrators, refer to- Figure 9. 45 is a constant speed shaft, which is made to rotate at a substantially uniform rate by any means whatever. i In the illus tration, I have provided shaft 45 with a disc 46 which rotates between a shifting electromagnetic field at 47, caused by a set of damper windings used in connection with a coil 48, were laminated iron core- 49, such as is common practice in Wattmeter art. This shifting field at 47 gives a fairly constant torque upon the disc 46, tending to rotate it. These several parts are also shown in Figure 10, which is .a view taken at right angles to Figure 9. Shaft 45 is provided with an escapement wheel 50, Figs. 9 and 10, and an escapement 51, Figs. 9 and 10, which escapement is connected to a pendulum 52. It may be well shown at this point why the torque on the disc 46 does not have to be exactly constant. In any oscillating system, such as the pendulum 52, the period-of oscillation is substantially constant for small increases and decreases in the amplitude of the pendulum. The period of such an oscillating system depends solely upon the effective mass and the restoring force, which tends to restore the mass to equilibrium. The damping effect of the pendulum due to the windage in the air, and the like, has no effect whatever upon the period of oscillation, and if this damping effect be proportional to the velocity of the swing of the pendulum and nothing else, it will serve as a means of absorbing the super- 7. fiuous energy caused by excessive torque on i at the disc 46, sothat supplying a pendulum with considerable damping losses, the excess energy may be taken up by the increased loss due to the additional damping effect which is due to increased amplitude, and without materially affecting the swing of the pendulum. 7

Of course, I do not limit myself to any such device for producing a constant speed of the shaft 45, as will be appreciated and more particularly pointed out in the appended claims. With this shaft 45 revolving at a constantspeed, we have available a definite time element, which we may utilize as the time factor in the integration process of the instrument 53' is a spherical segment which is free to revolve about an axis 54, parallel to the plane of the paper. The axis 54 is free to revolve about a second axis 55, which is pcrpcxuli .:nlar to the plane of paper inFig. 9 and which maybe better understood by reference to Figure 10. The axis 55 when rotated, carries with it the axis 54 which in turn carries with it the spherical surface 53. The shaft- 45 carries with it the wheel 56, which rotates the sphere about its axis 54', at a speed dependentupon the speed of the wheel surface 56, and the sine-of the angle theta, which will be appreciated by inspection of the figure. The sine of the angle theta is equal to the cosine of the anglephi. Thus the speed of the sphere 53 about its axis 54 is proportional to the diameter of the wheel divided by thecosine of the angle phi. At right angles to the plane containing the wheel 56 and the axis 55 is the wheel 57. The wheels 56 and a 57 are held gently against the surface of the sphere by the spring bearings 58, which spring bearings are shown in the right angle projection at 55).

The shaft 60 is free to rotate when driven by the sphere 53. The speed at which the wheel 57 is driven is proportional to that of the circle about axis 54 on surface 53, of the diameter proportional to the sine of the angle phi, divided by the diameter of the wheel 57. The diameters of the wheels 56 and 57 are substantially equal. Then, in order to find the relative ratio of gearing from wheel 56 to sphere 53 to wheel 57, take first the speed of the sphere which is proportional to the diameter of 56 divided by the cosine of phi multiply this value by the sine of phi, divided by the diameter of 57. The two wheel diameters cancel out, and give the relative speed represented by the sine of phi divided by the cosine of phi, which is trigonometrically equal to the tangent of phi. In other words, this ratio of gearing isproportional to the tangent of the angle phi, and the total number of revolushaft 60 will revolve a. number of revolutions proportional to the total flow of fluid when the instrument is calibrated.

Shaft 60 is connected to a gear train 61', which carries with a series of dials for facilitating the accurate reading of the revolutions of the shaft 60, the said'dials being shown in a right angle projection in Fig. 11, both of these being very common practice in the art.

Referring to Fig. 4, I show one means of served from Figs. 1 and 4, coils 64 and 65 are accomplishing this tangent-relation result heretofore referred to. 62 and 63 are two similar coils of wire wound preferably on an elliptic core, andwhich coils are shown in the right angle projection in Figure 10. At right angles to the said coil are two additional stationary coils, 64 and 65, Figs. 4 and 10. In the combined fields of these four coils, is an armature 66.

Source'of potential, 67,.Fig. 1, supplies f matically, the instrument may be compensatenergy for exicting the three instruments 0 Figure 4. Through conductors a and b, Figs. land 4, is obtained current for the coils 62 and 63, which current is'limited only by the resistance of the circuit and substantially only by the variable resistance 68, Fig. 4, so

that the field strength of the coils 62 and 63 is a function of the conductivit of the resist mice 68 and the voltage 0 the potential source, 67. We may speak of-this field as'a shunt field, and as will be shown presently,

coils 64 and 65'are series fields. As will be obconnected in series with the other two instruments shown in Fig. 4, with the resistor of the manometer 27 and the variable resistance d of Fig. 1 in circuit.

When potential source 67 generates voltage, shunt coils 62 and 63 produce a strong field at right angles to the direction of their winding, which 1s in the direction of the arrow 69, Fig. 4. Armature at 66 assumes a position such that its longest dimension lies in the direction of the arrow 69.

As the flow of gas impinges upon the-dynamic pressure tube 17 in Fig. 1, the mercury level at 31 in Fig. 5 rises in the chamber 30, the mercury coming into contact with the wire at 38 and at-35 and the like, causes current to flow in the line a, exciting the series coils 64 and 65 of Fig. 4. This'c'reates a field at right angles to 69 and in the direction 70. g The shuntand series fields combining vec- He's torially, and give the resultant field 71, and because of the relatively greater permeability of the armature in the direction-of its major axis, the armature assumes the direction ofthe arrow 71.

If the voltage of the potential source 67 rises, lowers,'alters its frequency, wave shape or constancy, the relative intensit of the shunt and series fields are unaltere so long as the shunt and series circuits have substantially similar characteristics, and therefore the angle phi does not change; even if the voltage ofthe potential source 67 be practically removed, the position of this angle re mains unchanged. However, of course, in-

the absence of a magnetic field about the 'armature at 66, it lacks stability of position.

It may be-well to point out here that there is no re uirement that the potential source 67 be one 0 an alternating current, although it is diagrammatically shown as such. 4 For the sake of simplicity I have shown the motive power for the timing element to be a phase shifting induction motor, such as used in wattmeters, and the lik'e, and designated by v the graphic meter 73 is egractly similar to the field and armature of the above described-integrator, as shown in Fig. 4 and Fig. 10, the

shunt'fields of 74 being connected in parallel tothe shunt fields of the integrator, and the series fields being connected in a series with the series fields ofsaid integrator. The shunt field of the graphic meter 73 is provided with a separate calibrating resistance 7 5, whichmeans that it may be calibrated or compensated independent of any other instrument. Onto the armature 76 of the element 74 is mounted a common form of arm and stylus 7 7 the deflections of which describe uponthe chart 78 as is common practice, and as will be appreciated'b those skilled in the art. The chart 76 may e driven by any constant speed device.

79 is an indicator, which has an electrical element 80, exactly similar to that of the graphic meter 73, but in addition may have its'pointer 81 gearedv to the armature of the aphically the changes in position of the sty us actuated by its motor element,

said meter element in order to give a greater spread of scale and a scale type more familiar in the art of steam measurement,

'As will beobserved,'t he divisions on thisscale are proportional to the tangent of the angle, which gives'a spread of scale at its beginning, permitting of better accuracy at lower readings,- due to not only the visibility of the scale but also to the influence oferrors at weaker field positions. I

However, it will be appreciated that this e of meter element may have a very intense field, and in general at even the zero position ofa pointer. Thus it may not be subjected to such gross errors as are found in square law instruments. It will also be noted thatthere are no springs required in the operation'of either one of the three instruments illustrated in Fig. .4, and thus they are not subjected to the large errors due to the effect of temperature on the springs, nor do they suffer the loss of calibration due to changes 1n the springs. The meter element 80 is similarly connected to that of the instrument 73. The shunt coil is connectedin shunt with the 7 other shunt coils of the flow meter, and the mechanically, and would be electrically, simi- I the art that the reading;

' by'a deflection method.

In Fig. 12 I show a second embodiment of this invention, by the construction of which I may eliminate the timing mechanism and make the shunt and series fields themselves perform this work.

- It will be appreciated by those skilled in the art, that a s unt electricmotor may be so designed that its light lo'ad speed is proportional to the armature voltage divided by the field voltage. Thus I present a second specifically difierentembodiment of my invention.

In order to construct a small shunt motor having sufficiently good characteristics for this purpose, I prefer to make it somewhat special, and in the embodiment I have shown a field and armature, which are constructed lar; except for the taps on the armature for bringing out the leads to the computator. In Fig.'12, 83 is a stationary casting to support the field laminations 84.. These laminations instead of being in radial planes at right. angles to the shaft 85, are wound spirally about the shaft center, as will be more clear- 1y understood by reference to Fig. 14, in which 84 are the laminations and 85the shaft. The armature is wound exactly similar, and

the teeth of the armature, face the teeth of the field, as illustrated at 86 and 87. 88'are the commutator leads, 89 the commutator and 90 and 91 the brush leads. It being a multiple field motor, the brush connected to lead 91 is not visible in the figure.

On shaft 85 is a; worm 92, which recordsthe revolutions of the said shaft on the dial 93, as is well understood in the art.

Shaft 85 is hollow, and has a .rod 94, fixed by a screw 95, and extending through said shaft to a point 96 forming a bearing for shaft 97, of the pointer 98, Figs. 12 and 13. Onto shaft 85, are fixed two permanent magnets 99 and 100, which revolve with said shaft, and between which said permanent magnets is the metal cup, 101, which is fixed to the shaft 97 and turns with it. Shaft 97 is prevented from turning by the weight 102,

Fig. 13, which is suspended by means of a flexible band, 103, over a-logarithmic'spiral cam, 104, this cam having the property, that motor and the position of the the distance of the flexible band 103 from the shaft center 105, is directly proportional to the angle through which the pointer 98 turns, this giving a counter torque to the said cam, 104, proportional to the angle through which it turns, which is the property of a spiral spring, but it eliminates from the instrument all the errors and variation dependent upon the usevof a spring in such a construction. As

the armature 106 turns, magnets 99 are taken with it, effecting the well known eddy-current drag upon the cup,- 101 ;-deflecting the pointer 98 through an angle directly proportional to the speed of the armature, 106. The pointer 98 is provided with an indicating scale, 107, and a revolving chart 108 and a stylus 109.

The chart 108 is made to revolve at a fixed speed by any suitablem'eans, as heretofore referred to, under the description of the first embodiment of a graphic meter.

When the armature 106 is made to revolve,

the number of revolutions are recorded on the dials 93, the instantaneous speed is recorded on. the scale 107 and a graph of the various instantaneous speeds is recorded on the chart 108 by the stylus 109.

Thus it remains only to be shown that the speed of the armature 106 is proportional to the flow of the pipe line '4, Fig. 1, in orderito complete the specifications oflthis embodiment of my invention. J

I illustrate a connecting board, 110, a common form .of plug, 111, and 112, showing different systems, by which this integrator may be connected. In general it may be said use of plug 112, which operates the armature in shunt and the field in series, though I may 4 that I prefer the connection effected by the lar application and with the particular motor characteristics-exhibited bythe integrator in Fig. 12; and it is believed that the magnitude of these combinations is suohthat nothing of importance can be added to this specification is equally applicabletoa recorder, as well' as to an integrator, provided in the case ofthe integrator .a proper trigonometric function or combination thereof is used. Referring to Figure 15, 113 and 114 are the shunt field coils, and 115 is the aforementioned calibrating and compensating resistance. In-

stead of using an additional set of stationary the vector diagram illustrated in the figure, and this resultant 'fieldaligns itself with the which isto ber in the line of flow, having a cross-section ,40

field of the coils 113 and 114, giving the proper constant deflection to the pointer 121 independently of line,

voltage, frequency, or wave form,

If the plug 120 be used, the current through the series coil 116 is made to'fiow also through a part of the'shunt coil 117 and the resultant fieldsaadding, as before, vectorially, but with the proper proportioningof the shunt and series field strength in coil 117, the magnetic field in this coil may be gradually brought down to zero, and reversed in the opposite direction, thus giving a much broader spread of scale and one more uniform in divisions, if desired, being slightly crowded on the ends. This construction, tangent scale, and this property has to be taken into consideration when such an element is utilized.

What I claim-is:

1. In a pressure differential creating device for fluids, the combination with the conduit through5 which the fluid, the pressure of differentiated, flows, of achamgreater than that of the said conduit and conaimng a multiplicity of ducts each of a crosssection smaller than the aforesaid conduit,

' said ducts being disposed parallel one to the other, parallel tothe line of flow of the fluid and disposed over the entire cross-section of the aforesaid chamber. 1 v v 2. In a ressure differential creating device for fluids, the combination with the'conduit through which the fluid,- the pressure of which is tobedifierentiated, flows, of a chamber in the line of flow, having a cross-section greater than that of the said conduit and a series of flow modifiers comprising a multiplicity of ducts each of a cross-section smaller than the aforesaid'conduit. I 7 3. In a pressure differential creating device for fluids, the combination with the conduit through which the fluid, the pressure of plicity of ducts each of a cross-section smaller than the aforesaid conduit, said ductsbeing owever, does not give a disposed parallelone to the; othengrallel to the line of flow of the fluid, and posed over the entire cross-section of the aforesaid chamber.

4. In a pressure diflerentialcreating device for fluids, the combination with the conduit throu hwhich the fluid, the pressure of l which is to e differentiated, flows, of a cham'-- her in the line of flow, containing a multiplicity of ducts each of a cross-section smaller than the aforesaid conduit, said ducts being disposed parallel one to the other, parallel to the line of flow of the fluid, and disposed over the entire cross-section of the aforesaid cham- 5. Ina pressure differential creating device. for fluids, the combination with the'condmt through which the fluid, the pressure of which is to be differentiated, flows, of a chamber" in the line of flow, containin a series of flow modifiers comprising a multlplicityof ducts each of a cross-section smaller than the aforesaid conduit, said ducts being disposed parallel one 'to the other, parallel'to the line of flow of the fluid, and disposed over the entire cross-section of the aforesaidchamber.

6. In .a pressure differential creating device for fluids, the combination with the conduit through which the fluid, the ressure of which is to be differentiated, ows, of a chamber in the line of flow, having a crosssection greater than that of the said conduit and containin a multiplicity of. ducts each. of a cross-section smaller than the aforesaid conduit, and-a dynamic pressure ,device'disosed in the line of flow of the said fluid and m the said line of flow after the intake end of the aforesaid ducts.

7. In a ressure differential creating-device for fluids, the combination with the conduit throu h which the fluid, the pressure of which is to ediiferentiated, flows,of a chamber in the line of flow, having a cross-section greater than that of the said conduit and containing a multiplicity of ducts each of a cross-section smaller than the aforesaid conduit, said ducts being'disposed parallel.

line of flow of the said fluid and in the said line of'flow afterthe intake endof the afore said ducts. .c

8. In a pressuredifli'erential creating device forfluids', the combination with'the conduit throughwhich the fluid, the pressure of which is to be differentiated, flows, of a chamber in the line of flow, having a cross-'- section greater than that of the said conduit and a series of flow modifiers comprising ;a multiplicity of ducts each of a cross-section smaller than the aforesaid conduit, and a dynamic pressure device disposed; in theline of flow of the saidfluid and inthe said line of flow after the intake end of the aforesaid ducts. I

9. In a pressure diflerential creating device for fluids, the combination with the conduit through which the fluid, the pressure of which is to be diflerentiated,'flows, of a chamber in the lineof flow, having a cross section greater than that of the said conduit and a series of flow modifiers comprising a 'multiplicity of ducts each of a cross-section smaller than the aforesaid conduit, said ducts being disposed parallel one to the other, parallel to the line of flow of the fluid, and disposed over the entire cross-section of the aforesaid chamber, and a dynamic pressure device disposed in the line of flow of the said fluid and in the said line of flow after the intake end of the aforesaid ducts.

10. In a pressure difl'erential creating device for fluids, the combination with the conduit'throughwhich the fluid, the pressure of which is to be differentiated, flows, of a chamher in. the line of flow, containing a multiplicityof ducts each of a cross-section smaller thanthe aforesaid conduit, said ducts being disposed parallel one to the other, parallel to the line of flow of the liquid, and disposed over the entire cross-section of the aforesaid chamber, and a d namic pressure device disposed in the line of fluid and in the said line of flow after the intake end of theaforesaid ducts. 11. In a pressure differential creating device for fluids, the combination with the conduit through which the fluid, the pressure of which is to be differentiated, flows, of a chamber in the line of flow, containing a series of flow modifiers comprising a -multiplicity of ducts each of-a cross-section smaller thanthe aforesaid conduit, said ducts being disposed parallel one to the other, parallel to the line of flow of the fluid, and disposed over the entire cross-section of the aforesaid chamber, and a dynamic pressure device disposed in the line of flow of the said fluid and in the said line of flow after the intake end of'the aforesaidducts.

12. In a differential pressure creating device for'fluids, a chamber in the line of flow of the fluid containing a multiplicity of ducts distributed over the entire area of the cross section of the said chamber, said ducts being supported by and carried through a wall over MONTFORD MORRISON.

flow of the said' ios the entire aforesaid cross-section and extending from the said wall into the said chamber in the upstream direction and permitting the fluid to flow through the aforesaid chamber only through said ducts, the space in the aforesaid chamber adjacent the up-stream side of the said wall having a dynamic-pressure pipe connection, whereby the dynamicpressure produced in the said pipe is inte- 

